1. Field of the Invention
The present invention relates generally to network devices and communication control methods, and more particularly to restoration of a concentrator and a network. In the present application, a concentrator conceptually covers a repeater hub and a switching hub. The repeater hub is a basic hub used for 10BASE-T and 100BASE-TX. The switching hub is one of the concentrators used as an Ethernet terminal having a switching function: It serves to read a Media Access Control (“MAC”) address of a destination terminal and sends a packet to a port connected to the terminal.
2. Description of Related Art
Along with recent widespread LANs and WANs, a large number of network devices, such as personal computers (“PCs” hereinafter) and concentrators have been connected to a network like the Ethernet for frequent information sharing and communications.
The concentrator has many functions, including a repeater function and a link test function. The repeater function is one which repetitively relays a transmission signal. The link test function is one which prevents malfunctions in a hub due to noises at the time of disconnection or release of an Unshielded Twisted Pair Cable (“UTP”) that connects devices that mutually send a link test pulse.
When a concentrator has an error or a “bug”, the concentrator cannot provide the above functions, resulting in an outage of network communications in a wide area. In such a case, the network is required to be restored before the cause is investigated. An exchange or replacement of the concentrator would restore the network, but the exchange is uneconomical and a reset of the concentrator would often lead to restoration of the network without the replacement according to experience. Therefore, a network administrator usually resets the concentrator by manual operations.
The manual operation has been used due to a fact that the breakdown frequency of the concentrator is not very high. Since a network administrator often serves another job in some companies, he delays resetting the concentrator, and disadvantageously causes outage of network communications for a long time. On the other hand, when the concentrator is reset for every defect, the number of resets becomes so large, hindering the smooth network communications instead.
Accordingly, it is an exemplary object of the present invention to provide a novel and useful concentrator and a reset control method therefor, in which the above disadvantages are eliminated.
Another exemplary and more specific object of the present invention is to provide a concentrator and a reset control method therefor that may easily and reliably secure early restoration from an outage of network communications.